fix: properly type extractWorkflow return

Type `extractWorkflow` return as `ComfyWorkflowJSON | undefined` instead
of `unknown` for better type safety downstream.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/platform/remote/comfyui/jobs/fetchJobs.ts

@@ -6,6 +6,7 @@
  * All distributions use the /jobs endpoint.
  */
 
+import type { ComfyWorkflowJSON } from '@/platform/workflow/validation/schemas/workflowSchema'
 import type { PromptId } from '@/schemas/apiSchema'
 
 import type {
@@ -139,8 +140,12 @@ export async function fetchJobDetail(
  * The workflow is nested at: workflow.extra_data.extra_pnginfo.workflow
  * Full workflow validation happens downstream via validateComfyWorkflow.
  */
-export function extractWorkflow(job: JobDetail | undefined): unknown {
+export function extractWorkflow(
+  job: JobDetail | undefined
+): ComfyWorkflowJSON | undefined {
   const parsed = zWorkflowContainer.safeParse(job?.workflow)
   if (!parsed.success) return undefined
-  return parsed.data.extra_data?.extra_pnginfo?.workflow
+  return parsed.data.extra_data?.extra_pnginfo?.workflow as
+    | ComfyWorkflowJSON
+    | undefined
 }